Traditionally, deep-fat fried or "french fried" foods have been prepared by placing a large quantity of food in a frying basket and immersing it in a receptacle of hot oil. When the food has fried to the degree desired, the basket is then removed from the hot oil. In commercial operations, a rack is often provided above the oil receptacle for securing the basket. Immediately after removal of food from the oil, the basket can be hung on the rack to allow the excess oil to drain from the fried food. Heat rising from the oil retards solidification of the excess oil on the food and consequently aids it in draining from the food. The excess oil will fall into the receptacle for further use. Commercial basket racks are often designed to allow a basket hung on the rack to be rocked back and forth to facilitate drainage of the excess oil and loosen food portions which may attach to the basket during frying.
French fried potatoes and other deep-fat fried foods have generally not been available at locations other than restaurants having traditional french frying setups.
Providing a traditional french fry setup at non-restaurant locations is impractical. The cost of providing a full time cook would make the french fry product prohibitively expensive, and a traditional setup cannot be safely left unattended to be operated by a consumer. Additionally, large venting setups are necessary to avoid excessive odors and continual maintenance of such setups is required.
Machines for automatically frying individual portions of food have recently been developed. Existing machines of this type require that the consumer dump a frozen food product from a single portion container into a feed chute on the top of the machine. The chute guides the food product into a frying vat much as in prior restaurant french fryers where it will be fried in hot oil. After cooking, the fried food product is removed from the vat and dropped into a discharge chute which leads to an output location where the consumer has placed a container to catch the food products.
Although existing machines do permit consumers to french fry single portions of food products at non-restaurant locations, several problems exist with the prior machines. Firstly, when such machines are used to fry frozen food products, as they normally are, the temperature of the frying oil will drop drastically (up to 60.degree. F.) when the oil first contacts the frozen food. This temperature drop is undesirable as frying below optimum temperature results in a poorly fried product which retains more oil than desired. Secondly, existing machines do not adequately drain the excess oil from the fried food before delivering it to the consumer. Not only does the consumer ingest extra oil, but the finished fried foods looks greasy. Also, the extra oil falls onto the cup holder portion of the machine or otherwise passes into hard to clean areas of the machine. Thirdly, existing machines do not properly control or vent fumes and odors which result from the frying oil. As it is not practical to vent externally of a building, excessive odor will leave an undesirable cooking smell in the room.
One difficult aspect of deep fat frying of frozen foods is the drastic temperature drop which occurs in the oil when the frozen food product is immersed. It is desirable to cook the food product at a relatively constant temperature, for example, 350.degree. F. If the frozen food can substantially effect the temperature of the oil then the undesirable large temperature drop occurs. U.S. Pat. No. 3,210,193 discloses an attempted solution to the temperature drop problem. In this patent a small reservoir of very high temperature oil such as 395.degree. F. is responsive to a thermostatic demand in a larger cooking vat to pump the high temperature oil into the filled vat and attempt to maintain a constant temperature when frozen products are added. This type of system, however, is undesirable as it is too dependent upon the thermostatic control and more importantly requires heating of the oil to temperatures that result in rapid degradation of the oil.
It can be seen then that there is a demand for an improved machine and method which will permit consumers to deep-fat fry individual food portions without the disadvantages of existing machines.